Control method of knocking in engine

Abstract

Abstract PURPOSE:To control a knock without causing the reduction of torque, by performing delay angle control of ignition timing at detection of the knock while controlling air-fuel ratio to a rich state when its delay angle quantity exceeds a preset value. CONSTITUTION:A prescribed frequency signal Sa is fetched from a detection signal S of a vibration sensor 1 by a band pass filter 2, input to a noise level detector circuit 4 via a waveform shaping circuit 3, picked with a mean value in a prescribed period about the top dead center, obtained with a reference signal Sr, and compared with a directly input signal Sb by a comparator 5 to generate a knock sensing pulse Sp. This signal Sp is input to a knocking controller 6, to increase the ignition timing correction coefficient beta one by one due to a knock, if exceeding its maximum value betaLM, fix the coefficient to betaLM, and a fuel injection pulse width Ti is controlled by this signal by multiplying increase coefficient r to an existing effective pulse width Te and adding a pulse width Ts of operational delay, thus the injection quantity is increased at each continous knock. In this way, a rise of exhaust temperature or reduction of torque can be prevented.

Inventors

• 👤 Kazuo Kojima
• 👤 一雄 小嶋

Bibliographic Details